Measuring Power Spectral Analysis in dBvolts vs Frequency: Tips and Techniques

[paradox10]

when looking at a power spectral analysis dBvolts vs frequency (Hz), how can you measure the area under the curve of a specific frequency range using the width at half height? any ideas?

 

[leptonsoliton]

If you represent the spectral peak as some functional form (Gaussian, Loretnz, etc.), you could probably analytically (or semi-numerically) work out a connection between FWHM and area under curve for a specified frequency range. This wold be true if the parameterization fixed the shape of the curve given just the parameter FWHM. Then, the area is obtained by integrating this curve over desired frequency range. Of course, this will not be very accurate in general (unless your spectrum is well modeled by the analytical form). Else, you could use a sum of Gaussians, and do a fit. Easier to just numerically integrate your actual spectrum.

 

[charng]

Thank you for your question. I am happy to provide some tips and techniques for measuring power spectral analysis in dBvolts vs frequency.

Firstly, it is important to understand that power spectral analysis is a method used to analyze the frequency content of a signal. It is typically represented as a graph with frequency on the x-axis and power (in dBvolts) on the y-axis. The area under the curve of this graph represents the total power of the signal.

To measure the area under the curve of a specific frequency range using the width at half height, you can follow these steps:

1. Identify the frequency range of interest on the power spectral analysis graph. This can be done visually or by using the frequency markers on the graph.

2. Find the peak of the curve within the frequency range of interest. This peak represents the frequency with the highest power.

3. Determine the half power point on either side of the peak. This is the point where the power is half of the peak power. You can do this by drawing a horizontal line from the peak power and finding where it intersects the curve.

4. Measure the distance between the two half power points. This distance represents the width at half height.

5. Calculate the area under the curve by multiplying the width at half height by the peak power. This will give you an estimate of the total power within the frequency range of interest.

It is important to note that this method is an approximation and may not be accurate for all types of signals. It is also affected by the shape and width of the curve. Therefore, it is recommended to use this technique as a rough estimate and not for precise measurements.

Other techniques for measuring the area under the curve of a specific frequency range include using integration software or manually calculating the area using numerical methods. However, these methods may require more advanced mathematical skills and may not be necessary for most applications.

I hope this helps and provides some guidance for measuring power spectral analysis in dBvolts vs frequency. If you have any further questions, please do not hesitate to reach out. Best of luck with your analysis!